Prior to the advent of the instant invention, prosthodontic systems have been extremely labor intensive and time consuming, requiring a considerable amount of skilled labor to custom fit prosthodontics for each case. Examples of a prior art prosthodontic systems include the Lava™ Zirconium CAD/CAM-CNC Crown Coping and Infrastructure System offered by 3M ESPE, and the Camlog Implant System's Ti-Ceramic Abutment. The Lava™ System utilizes a zirconia block which is CNC shaped in a greenware state that is then ceramic infused and heat sintered. The Camlog Implant System and other implant systems, utilize a two-piece abutment comprised of an upper sintered ceramic (zirconia) portion of the abutment that requires modification and a lower metal portion of the abutment that is screw affixed to the implant in the location in which a tooth replacement is necessary in the patient's mouth. The ceramic portion of the abutment, which is cemented to the metal portion in the lab prior to constructing the crown coping, simulates a laboratory analog of a prepared tooth stump base for fabrication of a custom crown coping, such as a Lava™ crown coping. It is noted that crown copings can also be fabricated from built-up powder as in the Vita/Vident Inceram/Zirconium System. It is noted also, all Ceramic crown systems at present require some type of ceramic base coping to be made first and then layered with porcelain to create the highly individualized likeness of the original tooth that is being replaced.
In the present system, when a patient requires a tooth replacement, a three-dimensional stone model of the patient's mouth is prepared from a master impression. If a two-piece abutment such as the Camlog Implant System's Ti-Ceramic Abutment described above is to be utilized, a lab technician will use the model of the patient's mouth to fit the metal portion of the abutment into the appropriate implant analog location in the model. The ceramic portion of the abutment is placed on the metal portion and the technician then modifies the ceramic portion by grinding down the factory sintered Zirconia ceramic piece so that its shape is appropriate for the location and orientation in which it will best support the final crown positioned within the patient's mouth. Once the ceramic portion of the abutment is modified to its final shape, the abutment, which is located in the model, is scanned. Using data from the scan about the shape and orientation of the abutment, as well as the existing teeth surrounding the position of the abutment, the necessary shape of a crown coping is determined and the crown coping is manufactured. In the context of the Lava™ System, a Computer Numeric Control (CNC) milling machine is utilized to manufacture the coping by milling a Lava™ block. Once the coping is completed, and built-up with porcelain to resemble a natural tooth, the entire piece (coping and abutment) is ready for placement in the patient's mouth. The crown coping/crown is cemented conventionally (like any crown to a tooth) to the installed abutment.
The prior art system described above is very time consuming, as it requires a considerable amount of labor and time to modify the abutment and then separately manufacture the coping based upon the shape of the modified abutment. In some cases, the ceramic portion of the abutment requires considerable modification due to its orientation within the patient's mouth such that a relatively small surface of the abutment remains for mounting of the coping. It is noted that a ceramic infiltrated sintered abutment is extremely hard to cut, compared to its greenware stage. In addition, the prior art system results in substantial waste of materials as the ceramic abutment and the coping are manufactured independently and/or by different processes and/or materials. Therefore, it would be beneficial to provide a system for simultaneously manufacturing a custom dental crown coping and ceramic infrastructure (abutment or ceramic portion of the abutment if two piece) to reduce the amount of labor, time and materials.